A mobile communications technology is used for supporting a user equipment (User Equipment, UE for short) in accessing the Internet through a wireless network. In order to access the wireless network, a UE first needs to be registered with an operator to obtain a legitimate subscriber identity module (Subscriber Identity Module, SIM for short) card, and then the SIM card is placed into the UE. The SIM card is a typical universal integrated circuit card (Universal Integrated Circuit Card, UICC for short) and includes subscription information of the operator. The UE uses the subscription information provided by the SIM card for network registration. SIM cards are gradually applied in the field of machine communications (for example, field data acquisition) and used for wireless network access and interaction with a service server in machine communications. However, because a device for machine communications is stationary after installation, for example, in a remote area, it is also difficult to change a SIM card after the SIM card is placed into a user equipment, and when a service provider needs to change an operator, it needs a large cost to change the SIM card in the user equipment, which brings about many difficulties in deploying a machine communications service. In order to solve the foregoing problem, the prior art provides a new-type UICC technology, that is, an embedded UICC (Embedded UICC, eUICC for short). The eUICC technology allows dynamic update of operator information in a UICC, that is, an operator can be changed without a need of removing a UICC from a user equipment.
When the UE into which an eUICC is placed accesses a wireless network, congestion may occur in the wireless network, for example, a device in the network is overloaded, or a UE consumes excessive network resources. To handle this situation, the prior art supports a congestion control method, in which when network congestion occurs, the network rejects access of a new user equipment and sets a limitation that a rejected user equipment cannot initiate an attach request or other service requests including a request to the network or another network within a time period (for example, 30 minutes). However, this method does not consider a feature and a requirement of a service running on a user equipment. If a service that is being executed or is to be executed by a current user equipment has a requirement for real time, for example, a medical device reports a condition of a patient, or a vehicle-mounted electronic device obtains surroundings information for navigation, and if the foregoing congestion control technology is used to prevent the user equipment from accessing a network in a time period, and the service cannot be executed properly and even a serious consequence is caused.